Читать книгу Life Histories of North American Jays, Crows, and Titmice - Arthur Cleveland Bent - Страница 41
ОглавлениеHABITS
The California jay of the interior is now known by the above name. Under its former name, Aphelocoma californica immanis, the 1931 Check-list gives its range as “extreme southern Washington, valleys of Oregon between the Cascades and the Coast ranges, and the Sacramento and San Joaquin valleys of California and adjacent mountain slopes.”
Dr. Grinnell (1901) in describing it, from specimens taken near Scio, Oreg., gave as its characters, “in coloration similar to Aphelocoma californica, but size greater and tail proportionately much longer.” This description was apparently based on only four birds, at least the measurements of only four are given, all from the Willamette Valley, Oreg. Mr. Swarth (1918), with a much larger series from a much larger area does not agree exactly with Grinnell’s description; he says that immanis is “distinguished from A. c. californica both by large size and pale [italics mine] coloration; from oocleptica by pale coloration, size being about the same.” At the time that Dr. Grinnell described immanis the characters and the distribution of the California races of Aphelocoma were not so well understood as they are today, and the fact had not been recognized that the two coastal races are dark colored and the interior race is paler. Ridgway (1904) does not recognize immanis but lists it as a synonym of californica.
Grinnell, Dixon, and Linsdale (1930) call this bird the interior California jay, an appropriate name. They say of its haunts in the Lassen Peak region: “This species, belonging to the brush-covered portions of the section, found suitable surroundings on the western slope of the section where the following kinds of plants grew: buck-brush, scrub oak, elderberry, hazel brush, manzanita, red-bud, grapevine. Individuals were also often seen in trees, but, as a rule, in their lower portions. The kinds of trees thus frequented were: blue oak, willow, living or fire-killed digger pine, knobcone pine, cottonwood, valley oak, sycamore, box elder, and orchard trees. In the eastern part of the section the jays frequented the slopes that were juniper covered. In addition to the junipers they were seen in mountain mahogany, sage-brush, and willows (in the canons).”
Nesting.—The nesting habits of the long-tailed jay are apparently similar to those of the other California races, and the eggs are practically indistinguishable. The measurements of 40 eggs average 28.4 by 21.0 millimeters; the eggs showing the four extremes measure 31.2 by 21.3, 27.4 by 22.0, 25.0 by 20.0, and 26.5 by 19.5 millimeters.
Young.—Grinnell and Storer (1924) have written quite fully on the habits of this subspecies, some of which may well be quoted here. While watching the two parent birds feeding their young, they noted that—
the parent birds had a particular route in approaching and leaving the nest, and this route was adhered to strictly. They would always approach through the trees of a wooded slope to the east, and then, having reached the nest tree, hop by easy stages to a position on the west side of the nest. From there the nestlings would be fed, and then the nest cleaned. After that the bird would work out of the south side of the willow, fly to a digger pine across the creek immediately above our tent, hop upward until near the top of the pine, and from there would take off in a direct course to its next forage ground. Even when the jays had been hunting insects in the open area immediately west of our camp, they would circle about when ready to return to the nest and approach it from the east. Only one adult visited the nest at a time although they often followed one another in quick succession. Save for the low crooning given when standing over the young, no calls were uttered while the parents were in the vicinity of the nest. There was a “zone of quiet” about their home, within which the owners would not call or raise any alarm.
Behavior.—Of its behavior they say: “The Interior California Jay is notoriously bold and forward in its behavior; although it is counted as a nonflocking species, individuals and pairs will gather quickly in response to the excited calls of one of their kin. The birds seem never to be so busy with their own affairs that they cannot stop and investigate any object of an unusual nature. Ordinarily this jay is the picture of animation. Perched, it stands in an attitude of alertness, its head up, tail straight back or tilted slightly upward, and feet slightly spread. Just after alighting a jay will often execute a deep bow involving the entire body, and this may be repeated a number of times and in different directions. The purpose of this bowing is not clear to us.”
Mrs. Ruth Wheeler writes to me of her experience with this jay: “I had a very interesting experience last year photographing a family of the California jay. We found the parents to be extremely wary. I have never worked with birds that appeared to show as much intelligence. We set up our bird blind near their nest, which was in a young oak, and only about 4 feet from the ground. Although the birds had become used to the blind and were nowhere to be seen when we entered, still they appeared to know that we were there. They came back very quietly, slipping through the trees and alighting near the blind. Then one of them leaned over and peered through the small opening through which the camera was focused. After looking very carefully, he saw us and set up a great outcry. We were able to get only one picture of the nest, which we took with a flash. After that the birds would not come near while we were in the blind.”
Voice.—Grinnell and Storer (1924) describe the notes of this jay as only slightly different from those of the other subspecies, but they add to our knowledge of the bird’s varied vocabulary, perhaps a limited language. Grinnell gives “cheek, cheek, cheek, etc., staccato, 3 to 10 times in rapid succession; chú-ick, chú-ick, chú-ick, etc., usually in 3’s slowly; schwee-ick, higher-pitched, 2 to 6 times, uttered still more slowly.” Storer adds: “A series of mildly harsh notes, kwish, kwish, kwish, uttered usually 3 to 5 times in quick succession; a more protracted softer note, kschu-ee, or jai-e, usually given singly. Birds of a pair when foraging together, and young and adults when in family parties, utter a subdued guttural krr’r’r’r’r. When attending young still in the nest, the parent birds utter a low crooning, impossible of representation in syllables; and the young birds, after leaving the nest and before gaining their living independently, have a ‘teasing scold’ which they utter almost incessantly, in keeping their parents apprised of their need for food.”
